When you create a servitor, you should be used to working with energy and have control over your own energy. This can be trained through meditation or aetherics exercises such as Tai Chi or Chi Gung. Further you should be proficient in visualisation.
Before you start creating a servitor you should plan exactly what it should do, what you wish to call it, how it should look like, what you will use as physical representation, how it should feed, what abilities it has, how long it should exist and how you wish to dissolve it after it has finished the task you set it on.
Planning your Servitor
Think about your desire, what is it exactly what you want, how could it be achieved, when do you want it. Take your time to come up with your answers. Visualise the future in which your will manifested itself and try to see what could have been affected by this manifestation. Is it worth it? Or does it create more problems than it solves? Find the best possible ways the desire could manifest so you eliminate unwanted sources.
If you still think that the manifestation will be worth it, write it all down in as much detail as possible.
Purpose of the Servitor
From what you have written down earlier you now form the purpose of the servitor. Here comes the best possible way to reach the desire into play. Depending on what purpose your servitor will have you can also incooperate perks such as knowledgeable in logistics or attractor of customers. These perks can be symbolised by traditional symbols such as planetary seals, runes, alchemical sigils etc.
Core of the Servitor
Now that you know the purpose of the servitor and its realms of influences you have to form a Statement of Intent from that. The Statement of Intent basically is the DNA of the servitor. It should be short and straight to the point.
Naming the Servitor
There are a few formulas for naming entities, for example you can form a single word from the previously created Statement of Intent, by eliminating all repeating letters and playing around with the remaining. Alternatively you can translate the Statement of Intent into a different language and do the same.
Review the purpose and perks of your servitor and go for symbolism that would make the appearance of the servitor looking good for you. Pick its gender, the shape of its body, the face etc. You can easily get some inspiration by reading the ancient grimoires of Solomon and Armadel for example.
Additionally create a sigil from the Statement of Intent and incooperate it into the servitors appearance.
This is where the thought-form is stored. It also serves as an idol for you to interact with. If you are artistically inclined make a puppet in accordance with the appearance you have outlined earlier. Alternatively you can pick items that are meaningful to the purpose or failing all else any item that gets your attention and you feel appropriate.
If you want your servitor succeed in its task you will have to feed it energy. Sources of energy can be yourself, little sacrifices given to it, eg blood, semen, beverages, food or flowers, or you can make it feed of a different person.
The sacrifices can for example be offered on little plates in front of the physical representation or drippled upon it. Talking to the servitor and meditating in front of it can also be feeding sources.
The life span depends largely on its purpose, is it a one-timer or should it go on indefinitely, do you want it to exist even after it has completed its task? Also choose how the servitor should be terminated.
Once you have completed this planning stages you are prepared to give life to the servitor.